1. Field
The present invention relates to combustion engines, more specifically, an internal combustion free-piston engine.
2. Description of Related Art
Conventional internal combustion engines today consume vast amounts of fuel and do not harness the maximum potential of the amount of energy created by combustion. Thus creating a loss of use of the potential energy and wasting fuel. The traditional internal combustion rotary engine relies on the Revelutions Per Minute (RPM) for idle and increasing horsepower and torque. As a four-stroke engine introduces fuel and air into a cylinder, the RPM of the engine directly affects the amount of time the combustion cycle has before it is exhausted from the cylinder. At higher RPMs todays internal combustion rotary engines do not have enough air or time to completely combust the fuel therefore exhausting un-burnt fuel and carbon from the cylinders into the exhaust, creating the necessity of a catalytic convertor for further burning emissions out of the exhaust gases. Pollution has always been an issue when referring to the internal combustion engine along with the excessive amounts of fuel required to power them. These issues have forced humanity to search for cleaner burning and a more abundant renewable fuel source. Even as today's engine operates at idle, waiting to be utilized, it is consuming fuel, therefore wasting fuel. Conventional engines do not have the ability to fluctuate compression when desired nor can they create more torque when required.
Considering prior art, a multiple of different internal combustion engines and methods for controlling the combustion cycle have been invented solving various issues with said conventional engines, for example see U.S. Pat. Nos. 692,218, 4,539,946, 6,722,322, 7,194,989, 7,823,546, 8,215,112, 8,662,029, 8,746,200, 8,757,126, and 8,997,699.
Prior art in U.S. Pat. No. 692,218 is a free-piston explosive engine that consists principally of a valve mechanism for controlling the speed of the engine and regulating the supply of air and fuel to the cylinder as well as an effective means for returning the piston on the return stroke. It also provides a means of making the engine self-starting.
In U.S. Pat. No. 4,539,946 a “Method of Controlling the Combustion Cycle in a Combustion Engine” that regulates the amount of fuel that is drawn into the engine and retains a certain amount to be compressed and used while a portion flows out without being compressed.
U.S. Pat. No. 6,722,322 an “Internal Combustion Engine” issued on Apr. 17, 2002 is an engine having at least one cylinder with two cylinder heads interconnected by one cavity. It states the engine cylinder configuration substantially increases the volume to enhance efficiency.
An “Energy Efficient Clean Burning Two-stroke Internal Combustion Engine” issued Mar. 27, 2007, U.S. Pat. No. 7,194,989 is a precision cast engine having a piston unit and a rotor unit to translate linear thrust from the piston unit into rotary power.
U.S. Pat. No. 7,823,546 entitled “Super Charged Engine” issued Nov. 2, 2010 is an engine with an output shaft extending through the engine block and generally parallel to the piston, the engine includes a boost piston cylinder integral to the cylinder, and a boost piston for producing compressed air so as to supercharge the engine.
A “Free Piston Stirling Engine”, U.S. Pat. No. 8,215,112, is a free piston sterling engine comprising a power piston fitted into a cylinder and further includes; a support structure carrying moving magnets for linear alternator; and a passive structure that at normal operating power and frequency produces a restoring force on the piston in the absence of contact with the cylinder.
Another example in U.S. Pat. No. 8,662,029 is a linear combustion engine having a cylinder with a combustion section in the center portion of the cylinder and a pair of opposed piston assemblies adapted to move linearly within the cylinder.
In U.S. Pat. No. 8,746,200 a “Reciprocating Piston Internal Combustion Engine with Mass Balancing Device” relates to a reciprocating-piston internal combustion engine having at least one engine cylinder and piston oscillating therein and having a balancing mass which is driven by a crankshaft.
Issued Jun. 24, 2014, U.S. Pat. No. 8,757,126 is a non-reciprocating piston engine with pistons that follow a circular motion and respective cylinders follow a counter-circular motion relative to the pistons, such that each piston follows a linear path relative to the respective cylinder and at least a top surface of each piston remains within the cylinder throughout engine operation resulting in a stroke length four times the radius of the circular motion.
U.S. Pat. No. 8,997,699 is a linear free piston combustion engine with indirect work extraction via gas linkage having a cylinder with two opposed free pistons disposed therein that form a combustion section in a center of the cylinder with each piston having a front face and back face, where two opposed extractor pistons in their own cylinders at opposite ends of the free piston cylinder and two gas linkages and each extractor piston is connected to a rotary electromagnetic machine.
After acknowledging prior art, it is desirable to provide an engine that overcomes the issues mentioned above that uses less fuel and more completely combusts the fuel creating higher efficiency and less pollution by controlling the length of the combustion cycle. By providing an engine that can utilize various combustible fuels, does not idle, is not rotary, has fewer parts, is more cost effective to manufacture, and harnesses and stores the maximum amount of potential energy until needed, it is evident the efficiency will surpass that of the conventional internal combustion engine; which is currently around 35%-40%. It is also desirable to provide an engine that doesn't require a compression stroke to complete a cycle and stores the energy created by combustion until needed, therefore allowing the engine components to last longer because of less wear and tear and having more time to cool in between cycles.